Witkoff made the comments in a CNN 'State of the Union' interview after being asked about Israel's decision to postpone the release of Palestinian prisoners and detainees and how he expected the ceasefire to be impacted by developments in the region.
"We have to get an extension of phase one," Witkoff said. "I'll be going to the region this week, probably Wednesday, to negotiate that."
Israeli Prime Minister Benjamin Netanyahu's office said on Sunday Israel was waiting to deliver 620 Palestinian prisoners and detainees "until the release of the next hostages has been assured, and without the humiliating ceremonies." Hamas handed over six hostages from Gaza on Saturday.
Some Israeli hostages and Palestinian prisoners and detainees have been released as part of a three-phase ceasefire in Gaza that went into effect just before Trump took office on January 20.
The U.N. human rights office has described images of both emaciated Israeli hostages and Palestinian detainees released as distressing, saying they reflected the dire conditions in which they were held.
Palestinian officials have cited the blindfolding and binding of hands of Palestinian prisoners and detainees and warnings against holding celebrations at their release as examples of their humiliation by Israeli authorities.
Israel cites Hamas making hostages appear on stage in front of crowds and sometimes speak before they are handed over, as well as parading coffins with hostage remains through crowds.
Witkoff told CNN that Netanyahu was "well-motivated" and that Hamas cannot continue to govern Gaza.
U.S. ally Israel's military assault on Gaza has killed more than 48,000 Palestinians since October 2023, according to the Gaza health ministry, and led to accusations of genocide and war crimes that Israel denies. The assault internally displaced nearly Gaza's entire population and caused a hunger crisis.
The latest bloodshed in the decades-old Israeli-Palestinian conflict was triggered on October 7, 2023, when Hamas attacked Israel, killing 1,200 people and taking some 250 hostages, according to Israeli tallies.
Trump himself has faced international condemnation for his proposal to take over Gaza and permanently displace Palestinians there. Rights experts and the United Nations have called it a proposal for ethnic cleansing.
